Proceedings of the National Academy of Science of the United States of America |  August 06, 2021

Multicomponent nature underlies the extraordinary mechanical properties of spider dragline silk

Authors: Nobuaki Kono1,2, Hiroyuki Nakamura3, Masaru Mori1,2, Yuki Yoshida1,2, Rintaro Ohtoshi4, Ali D. Malay4, Daniel A. Pedrazzoli Moran3, Masaru Tomita1,2, Keiji Numata4,5 and Kazuharu Arakawa1,2*


  • 1. Institute for Advanced Biosciences, Keio University
  • 2. Systems Biology Program, Graduate School of Media and Governance, Keio University
  • 3. Spiber Inc.
  • 4. Center for Sustainable Resource Science, RIKEN
  • 5. Depertment of Material Chemistry, Kyoto University

From "Multicomponent nature underlies the extraordinary mechanical properties of spider dragline silk" Use approved by copyright holders.


Dragline silk of golden orb-weaver spiders (Nephilinae) is noted for its unsurpassed toughness, combining extraordinary extensibility and tensile strength, suggesting industrial application as a sustainable biopolymer material. To pinpoint the molecular composition of dragline silk and the roles of its constituents in achieving its mechanical properties, we report a multiomics approach, combining high-quality genome sequencing and assembly, silk gland transcriptomics, and dragline silk proteomics of four Nephilinae spiders. We observed the consistent presence of the MaSp3B spidroin unique to this subfamily as well as several nonspidroin SpiCE proteins. Artificial synthesis and the combination of these components in vitro showed that the multicomponent nature of dragline silk, including MaSp3B and SpiCE, along with MaSp1 and MaSp2, is essential to realize the mechanical properties of spider dragline silk.

-> Read full paper
-> Press release (Japanese only. English press release will be available at a later date.)

Spiber’s research initiatives into novel protein materials have benefited from grants and subsidies from Tsuruoka City, Yamagata Prefecture, and Japan’s ImPACT program.